The present invention relates to a vehicular headlamp provided with a reflector having a low-beam reflecting surface and a high-beam reflecting surface disposed closely adjacent one another vertically.
Generally, four-beam headlamps for a motor vehicle provided with separate low- and high-beam reflectors are well known. The low- and high-beam reflectors may be disposed either vertically or laterally adjacent one another.
A headlamp provided with a reflector formed by integrating the low- and high-beam reflectors has also been disclosed. In this case, the reflector has a structure in which the low-beam reflecting surface and a high-beam reflecting surface are disposed closely adjacent one another. Examples of such headlamps are disclosed in U.S. Pat. Nos. 5,353,203 and 5,702,174.
In order to improve the driver's view at night, it is required to provide a high yield of luminous energy of not only the low beam but also the high beam. Particularly, the driver of a vehicle such as a truck, RV, or large-size passenger car may be likely to drive long distances or drive on country roads at night in situations where the high beam is kept ON for long periods. In such a case, it is especially important to obtain a sufficiently high yield of luminous energy.
In the conventional vehicular headlamp provided with a reflector having low- and high-beam reflecting surfaces disposed closely adjacent vertically, the focal distances of both reflecting surfaces are the same. It has been found, however, that such an arrangement may fail to establish a sufficiently great solid angle of the high-beam reflecting surface, resulting in an insufficient yield of the high-beam luminous energy.